Use of flowable composites for orthodontic bracket bonding.
OBJECTIVE
To test the bonding characteristics of four flowable composites for orthodontic bracket bonding.


METHODS
Metal brackets were bonded to acid-etched human enamel using four flowable composites (Grandio Flow, GF; UniFil Flow, UF; UniFil LoFlo Plus, UL; and DenFil Flow, DF), an orthodontic bonding system (Transbond XT, TX), and a restorative composite (Filtek Z250, FZ). After 24 hours of storage in water at 37 degrees C, a shear bond strength (SBS) test was performed. After debonding, the adhesive remnant index (ARI) was assessed. In addition, the flow and flexural strength of the materials were examined.


RESULTS
The SBS for the flowable composites ranged between 7.2 and 8.3 MPa, and TX showed a significantly higher value (mean 10.9 MPa). The flowable composites also demonstrated a significantly superior flowability, yet inferior flexural strength (except for DF) than TX and FZ. Two flowable composites (GF and UL) produced significantly higher ARI scores than TX and FZ, which represented a larger resin remnant on the enamel surfaces after debonding.


CONCLUSIONS
When considering the SBS and ARI scores obtained in this study, flowable composites with no intermediate bonding resin could be conveniently applied for orthodontic bracket bonding.
Ryou
Dong-Bum
DB
Department of Dentistry, Graduate School, Kyungpook National University, Daegu, Korea.
Park
Hyo-Sang
HS
Kim
Kyo-Han
KH
Kwon
Tae-Yub
TY
D000134:Acid Etching, Dental; D003188:Composite Resins / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry; D017005:Dental Debonding; D003743:Dental Enamel / Q000648:ultrastructure; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D016910:Orthodontic Brackets; D018583:Pliability; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
D003188:Composite Resins; C503708:Denfil Flow; D003722:Dental Alloys; C444701:Filtek Z250; C509998:Grandio; D011109:Polymethacrylic Acids; D019279:Resin Cements; C477790:Transbond XT; C510179:UniFil Flow; C501418:Unifil LoFlo Plus; C111840:flowable hybrid composite; D014867:Water